Rock history is infuriatingly vague on how a dental assistant from Northern California came to make an album with the assistance of the likes of Milt Holland, Shelly Mann, Oliver Nelson and Reinie Press. It offers no clues on why she apparently returned to obscurity soon after, with even her own record company denying all knowledge of Parallelograms. The Wild Places original CD reissue was sourced from a mint condition vinyl copy of this notoriously poorly pressed album - when the Brooklyn companys Michael Piper finally tracked her down the artist admitted that she had only played her own copy once, being so disappointed with its presentation. This second reissue is taken from Perhacs own reel to reel tapes, dubbed from the original masters in 1970 and subsequently lovingly restored.

So what of the music upon which all this care and attention has been belatedly lavished? In a snappy soundbite, Linda Perhacs sounds like Laura Veirs mum. They share the same fascinations  flora, fauna and topographical references seep, creep and swim through these songs  and also play similar entrancing tricks with language, blessed with a common ability to fracture and invert phrase and meaning. Often compared to Joni Mitchell, Perhacs takes the kind of wistful acoustic folk that can be found on Robertas early albums and infuses it with something gloriously lysergic. Chimacum Rain, for example, is a pretty, staggering three minutes with which to introduce a career, with a chorus waterfall of vocal overdubbing that drifts into moments of intense realisation (Im spacing out/Im seeing silences between leaves) before encountering stretches of hectoring disorientation. The elastic, electric Paper Mountain Man suggests Grace Slick covering Fred Neils Thats The Bag Im In, and even the albums least adventurous moments  for example, the Aquarian age hangovers of Dolphin and Call Of The River  shimmer with the kind of diaphanous haze to which Tim Buckley often aspired but less frequently achieved.

The title track begins with more experimental multitracked harmonies that fully justify the oscillating lettering employed for this entry in the printed lyrics, before sailing far out on waves of dark disquiet. Its immediately followed by Hey, Who Really Cares, whose gorgeous melancholia and impressionistic lyrics (I used to think of ferris wheel light sounds/The Friday hum of new and blue) could easily have become something for milkmen to whistle had the Carpenters got hold of it. She once again summons up a flicker of Grace Slick during Porcelain Baked Cast Iron Wedding, almost spitting the phrases at times. The albums most upbeat moment, a kaleidoscopic explosion of language, it nevertheless sounds to these ears like a bitter sideswipe at fashion industry jetsetters.

Those aforementioned reel to reel tapes also contained a cache of extra material, which is released for the first time here. Despite the intriguing excellence of Parallelograms proper, for me its in these bonus tracks that Perhacs genius is at its most concentrated. A new song, If You Were My Man, is represented in both demo and studio configurations, although the former so outpaces the latter in terms of energy and inventiveness it might be wondered whether the tracks descriptions have been accidentally transposed in the packaging. Nevertheless, both are luminous examples of her more commercial work, but even then bristling with shivery tactility. An alternative version of Hey, Who Really Cares grows an introduction of heartbeat and accelerating media collage, preceding and pre-empting Dark Side Of The Moon by three years. Finally, there are a brace of Chimacum Rain demos  both lovely - along with Perhacs own recorded effects suggestions to her producer.

The music contained on this second CD issue of Parallelograms encompasses absolutely everything Linda ever recorded  she expressed her musical self entirely in this hour of fragile folkadelia. Destined to remain one of popular musics eternal one-shot what ifs, alongside the likes of Grace, Miss America and Oar, as Michael Piper writes in his informative, if too brief, booklet notes, What a legacy and gift she has created here.